Businesses expend considerable resources on understanding user engagement on a given platform in order to provide better services and maintain users' attention. Different things compete for users' time and attention, so it is important for businesses to understand how the users interact with a particular site or service. Thus, analyzing user engagement is an important tool for understanding user behavior.
A common approach to analyzing user engagement is to count atomic user actions, such as viewing a page, creating a blog post, or writing a comment. Unfortunately, focusing on aggregate user action counts reveals little about the behavior of the underlying user population. Without an explicit characterization of the distribution of user activity, it may be difficult to assess the significance of the metrics or understand the underlying changes in user behavior affecting them.